Write a Formula for the General Term (The Nth Term) $$\mathbf { a } _ { \mathbf { n } }$$

Multiple Choice

Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for $$\mathbf { a } _ { \mathbf { n } }$$ to find $$a _ { 20 }$$ , the 20th term of the sequence.
- $1,5,9,13,17 , \ldots$

A) $a _ { n } = 4 n - 3 ; a _ { 20 } = 77$
B) $a _ { n } = 3 n - 4 ; a _ { 20 } = 56$
C) $a _ { n } = 4 n + 3 ; a _ { 20 } = 83$
D) $a _ { n } = n + 4 ; a _ { 20 } = 24$